Science and technology

Environmental models undergo international test

Article Abstract:

The International Atomic Energy Agency (IAEA) conducted a blind-test to evaluate several assessment models with radiation exposure data from the 1986 Chernobyl nuclear accident. The IAEA compared the computer models' abilities to simulate transport of fallout to the environment and human exposure against real world indicators from Finnish contamination data. The models were not able to predict time-dependent endpoints, such as quarterly cesium concentrations in milk, better than time-averaged or time-integrated endpoints.

Bisulfate-mediated borohydride reduction of dye azo bonds for the regeneration of dye-saturated quaternized cellulose proves to be an efficient method for the decolorization of textile wastewaters. Modified cellulosics containing quaternary ammonium groups were found to react strongly with anionic dyes and can be utilized as ion exchangers to remove textile dyes from wastewater. Results also indicated that bisulfite bonded strongly with the dyes but did not split the dye's azo bond.